The subject invention relates to an improved nozzle for use in dispersing fuel, especially polyphase fuels, into a combustion boiler. It has been a problem to provide a dispersing nozzle that achieves excellent results with a variety of polyphase fuels and can operate over a substantial range of fuel flow rates. It is particularly desirable that such a nozzle be resistant to rapid wear by solid-bearing fuels, e.g., coal-bearing slurries. It also should be able to premix, or maintain a suitable mix, of a polyphase coal mixture.
One problem with earlier nozzles is that they utilized a relatively high velocity in the nozzle head, thereby, increasing erosion. Yet, such a high velocity was designed to achieve the desirable degree of dispersion and mixing behind the nozzles.